Drive control apparatus, drive control method, drive control program, and recording medium

ABSTRACT

A drive control apparatus ( 100 ) uses a calculating unit ( 103 ) to calculate a danger index indicative of the possibility of occurrence of a dangerous event for a mobile body based on information of the mobile body acquired by an information acquiring unit ( 101 ). A notifying unit ( 104 ) notifies a passenger of the possibility of occurrence of a dangerous event for the mobile body. A control unit ( 106 ) controls a driving unit ( 102 ) to stop the drive if a determining unit ( 105 ) determines that the danger index is greater than a predetermined value.

TECHNICAL FIELD

The present invention relates to a drive control apparatus that controlsa driving unit based on the possibility of occurrence of a dangerousevent for a mobile body, a drive control method, a drive control method,a drive control program, and a recording medium. However, theapplication of the present invention is not limited to the drive controlapparatus, the drive control method, the drive control program, and therecording medium.

BACKGROUND ART

Conventionally, vehicular-operation information output apparatuses existthat use a driving unit such as a robot to present informationconcerning car navigation to guide a vehicle to a destination as well aspresent information concerning the state of vehicular-operation in afamiliar and understandable manner.

Among such vehicular-operation information output apparatuses, anapparatus has been proposed that detects a state of a driver using acamera and stops the movement of the driving unit or terminates thedisplay on a display screen and sound output if the driver is watchingthe driving unit or the display screen, thereby preventing dangerousvehicular-operation caused by gazing at the driving unit or the displayscreen and achieving safe and proper navigation (see, e.g., PatentDocument 1).

Patent Document 1: Japanese Patent Application Laid-Open Publication No.2004-93354

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

However, for example, it is problematic in that if the driving unit orthe display screen is within the visual field of the driver even whenthe driver is not looking at the driving unit or the display screen, thedriver may mistake the movement and operation sound of the driving unitand the display of the display screen for an outside object that maypose a danger to the vehicle.

Means for Solving Problem

To solve the problems above and achieve an object, a drive controlapparatus according to the invention of claim 1 includes a driving unitthat drives a sensor mounted on a mobile body; an information acquiringunit that acquires information of the mobile body; a calculating unitthat calculates a danger index indicative of a possibility of occurrenceof a dangerous event for the mobile body based on the informationacquired by the information acquiring unit; and a controlling unit thatcontrols the driving unit based on a calculation result calculated bythe calculating unit.

A drive control method according to the invention of claim 8 includes aninformation acquiring step of acquiring information of a mobile body; acalculating step of calculating a danger index indicative of apossibility of occurrence of a dangerous event for the mobile body basedon the information acquired at the information acquiring step; and acontrolling step of controlling a sensor mounted on the mobile body,based on a calculation result calculated at the calculating step.

A drive control program according to the invention of claim 9 causes acomputer to execute the drive control method according to claim 8.

A computer-readable recording medium according to the invention of claim10 stores therein the drive control program according to claim 9.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a functional configuration of a drivecontrol apparatus according to an embodiment;

FIG. 2 is a flowchart of drive control processing by the drive controlapparatus according to the embodiment;

FIG. 3 is a block diagram of a hardware configuration of a navigationapparatus according to an example;

FIG. 4 is a block diagram of a functional configuration of a drivecontrol apparatus according to an example;

FIG. 5 is a flowchart of processing performed by the drive controlapparatus according to the example;

FIG. 6 is a flowchart of processing for acquiring vehicle informationand image information;

FIG. 7 is a flowchart of processing for calculating a first attentionpoint;

FIG. 8 is an explanatory diagram of a vertical distance of a point on aroad in a captured image;

FIG. 9 is an explanatory diagram of a relation between a horizontaldistance and a vertical distance from a center point of the capturedimage;

FIG. 10 is an explanatory diagram for explaining points on a road;

FIG. 11 is a flowchart of processing for calculating a control signal;

FIG. 12 is a flowchart of processing for controlling a driving unit;

FIG. 13 is a flowchart of processing for acquiring the imageinformation;

FIG. 14 is a flowchart of processing for calculating a danger index;

FIG. 15 is an explanatory diagram of the image information acquired attime T;

FIG. 16 is an explanatory diagram of the image information acquired attime (T+ΔT);

FIG. 17 is an explanatory diagram of the image information where whitelines are matched and overlapped;

FIG. 18 is an explanatory diagram of a motion vector M;

FIG. 19 is an explanatory diagram of degrees of the danger index Ddepending on the relationship between a unit vector I and the motionvector M;

FIG. 20 is a flowchart of processing for calculating a second attentionpoint; and

FIG. 21 is a flowchart of processing for determining whether recovery ofnormal vehicular operation has been achieved.

EXPLANATIONS OF LETTERS OR NUMERALS

100 drive control apparatus

101 information acquiring unit

102 driving unit

103 calculating unit

104 notifying unit

105 determining unit

106 control unit

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Preferred embodiments of a drive control apparatus, a drive controlmethod, a drive control method, a drive control program, and a recordingmedium according to the present invention will be described withreference to the accompanying drawings.

Embodiments (Functional Configuration of Drive Control Apparatus)

A functional configuration of a drive control apparatus 100 according tothe embodiment of the present invention will be described. FIG. 1 is ablock diagram of a functional configuration of a drive control apparatusaccording to the embodiment. As depicted in FIG. 1, the drive controlapparatus 100 includes an information acquiring unit 101, a driving unit102, a calculating unit 103, a notifying unit 104, a determining unit105, and a control unit 106.

The information acquiring unit 101 acquires information concerning amobile body. Specifically, for example, the information concerning amobile body is image information concerning the surroundings of themobile body captured by a camera mounted on the mobile body. Theinformation concerning the mobile body may be information acquired fromvarious sensors. The information acquired from various sensors may be,for example, speed/acceleration information of the mobile body; currentposition information of the mobile body; information concerning thevolume and direction of sound, temperature, humidity, intensity oflight, amount of smoke, components of air, contact with an arbitraryobject, pressure, degree of magnetic force, etc., inside and outside ofthe mobile body; information concerning the distance from the mobilebody to an arbitrary object; and information of heart rate, brain waves,respiration, etc., of a user.

The driving unit 102 drives sensors mounted on the mobile body. Thesensors mounted on the mobile body are the various sensors above andinclude, for example, an image sensor (camera). The driving unit 102 maydrive the information acquiring unit 101. Therefore, the informationacquiring unit 101 may be integrated with or independent of the varioussensors. The driving unit 102 drives the sensor or the informationacquiring unit 101 mounted on the mobile body in the yaw direction andthe pitch direction. The driving unit 102 may be a robot imitating ashape of a human or an animal, for example.

The calculating unit 103 calculates a danger index indicative of thepossibility of occurrence of a dangerous event for the mobile body basedon the information acquired by the information acquiring unit 101. Adangerous event means, for example, that the mobile body deviates from apath, that the mobile body contacts an object, or that a state of themobile body user is different from the normal state. The danger index isa numeric value serving as a reference representative of a degree of thepossibility of occurrence of such a dangerous event.

The notifying unit 104, depending on the calculation result calculatedby the calculating unit 103, notifies a passenger in the mobile body ofthe possibility of occurrence of a dangerous event for the mobile body.The notifying unit 104 makes notification through a warning sound, audioinformation, or a turning on of a light, for example. If notification isgiven through audio information, specifically, for example, potentialhazards to the mobile body are reported, such as “distance between carsis too short” or “obstacle exists on the right”. The possibility ofoccurrence of a dangerous event for a passenger, such as “air quality ispoor, open a window” or “turn down the audio volume” may be reported.Such notification of the possibility of occurrence of a dangerous eventmay be made through a driving of the driving unit 102.

The determining unit 105 determines whether the danger index calculatedby the calculating unit 103 is a value greater than a predeterminedvalue. The predetermined value may be set by a user or may be variedbased on past history. The determining unit 105 may determine whetherthe danger index has returned to a value smaller than the predeterminedvalue after it is determined that the danger index calculated by thecalculating unit 103 is a value greater than the predetermined value.

The control unit 106 controls the driving unit 102 according to thecalculation result calculated by the calculating unit 103. The controlunit 106 stops the driving of the driving unit 102 if the determiningunit 105 determines that the danger index is a value greater than thepredetermined value. The control unit 106 may resume the driving of thedriving unit 102 if the determining unit 105 determines that the dangerindex has returned to a value smaller than the predetermined value.

(Drive Control Processing by Drive Control Apparatus)

Drive control processing by the drive control apparatus 100 will bedescribed. FIG. 2 is a flowchart of drive control processing by thedrive control apparatus according to the embodiment. As depicted in theflowchart of FIG. 2, the information acquiring unit 101 acquiresinformation concerning the mobile body (step S201). The calculating unit103 calculates a danger index indicative of the possibility ofoccurrence of a dangerous event for the mobile body based on theinformation concerning the mobile body acquired at step S201 (stepS202). The notifying unit 104 notifies a passenger of the possibility ofoccurrence of a dangerous event for the mobile body (step S203).

The determining unit 105 determines whether the danger index calculatedat step S202 is a value greater than a predetermined value (step S204)and if the danger index is a value greater than a predetermined value(step S204: YES), the control unit 106 controls the driving unit 102 tostop the driving (step S205), and a series of the processing ends. Onthe other hand, if the danger index is not a value greater than apredetermined value (step S204: NO), the processing returns to stepS201, and subsequent processes are repeated.

Although the passenger is notified at step S203 in the flowchart of FIG.2, configuration is not limited hereto. Specifically, for example, theprocessing may go to step S204 without notifying the passenger.Alternatively, it may be determined whether the danger index is within apredetermined range having the predetermined value of step S205 as theupper limit and if the danger index is within the predetermined range,the passenger may be notified.

Although the driving of the driving unit 102 is stopped at step S205,configuration is not limited hereto. Specifically, for example, thedriving may be limited without stopping the driving of the driving unit102. The driving is limited in such a way that the drive range of thedriving unit 102 is narrowed or such that only the blinking of a lightor output of sound is performed while the driving unit 102 is stopped.

As described above, according to the drive control apparatus 100 of theembodiment, the calculating unit 103 calculates a danger indexindicative of the possibility of occurrence of a dangerous event for themobile body based on the information concerning the mobile body acquiredby the information acquiring unit 101, and the control unit 106 maycontrol the driving unit 102 that drives a sensor mounted on the mobilebody according to the calculation result calculated. Therefore, thedrive control apparatus 100 can control the driving unit 102 if it isdetermined that a dangerous event will occur for the mobile body evenwhen a user does not gaze at the driving unit 102, for example. Thisenables the driving unit 102 to be controlled and prevented frominterrupting the judgment of the user with respect to vehicularoperation during dangerous circumstances.

According to the drive control apparatus 100 of the embodiment, thepassenger of the mobile body may be notified of the possibility ofoccurrence of a dangerous event for the mobile body according to thecalculation result calculated by the calculating unit 103. Therefore,the drive control apparatus 100 may give a warning of dangerousvehicular operation circumstances to a driver if the danger index iswithin a predetermined range. This enables a user to know that thevehicular operation circumstances are dangerous and to avoid a dangerousevent such as an accident.

According to the drive control apparatus 100 of the embodiment, thecontrol unit 106 can stop the driving of the driving unit 102 if thedetermining unit 105 determines that the danger index is a value greaterthan the predetermined value. Therefore, the drive control apparatus 100may stop the driving unit 102 within the visual field of the driverunder dangerous circumstances to prevent the driving unit 102 from beingmistaken for an object outside the vehicle (such as a person or anoncoming vehicle). This enables a user to concentrate on operation ofthe vehicle since no distractive motion exists within the visual field.

According to the drive control apparatus 100 of the embodiment, thedriving unit 102 can drive the information acquiring unit 101.Therefore, a wide range of information can be acquired by driving theinformation acquiring unit 101 by the driving unit 102. This enables auser to extensively detect the possibility of occurrence of a dangerousevent.

According to the drive control apparatus 100 of the embodiment, theinformation acquiring unit 101 may acquire image information concerningthe surroundings of the mobile body. Therefore, an object with a higherdanger index for the mobile body may be identified from changes in theacquired image information. This enables a user to avoid a dangerousevent such as an accident.

According to the drive control apparatus 100 of the embodiment, thedriving of the driving unit 102 may be resumed if the determining unit105 determines that the danger index has returned to a value smallerthan the predetermined value. Therefore, the driving unit 102 can bedriven during normal vehicular operation, enabling a user to resume themovement of a robot, etc., mounted on the vehicle after a dangerousevent has been avoided even if the has been stopped.

According to the drive control apparatus 100 of the embodiment, thedriving unit 102 can drive a sensor mounted on the mobile body in theyaw direction and the pitch direction. Therefore, the drive controlapparatus 100 can extensively detect the information concerning themobile body. This enables a user to extensively detect the possibilityof occurrence of a dangerous event.

Example

An example of the present invention will be described. This exampledescribes a case of implementing the drive control apparatus of thepresent invention with a navigation apparatus mounted on mobile bodiessuch as vehicles (including four-wheel vehicles and two-wheel vehicles),for example.

(Hardware Configuration of Navigation Apparatus)

A hardware configuration of a navigation apparatus 300 according to theexample will be described. FIG. 3 is a block diagram of a hardwareconfiguration of the navigation apparatus according to the example. Asdepicted in FIG. 3, the navigation apparatus 300 includes a CPU 301, aROM 302, a RAM 303, a magnetic disk drive 304, a magnetic disk 305, anoptical disk drive 306, an optical disk 307, an audio I/F (interface)308, a microphone 309, a speaker 310, an input display 311, a video I/F312, a display 313, a communication I/F 314, a GPS unit 315, varioussensors 316, and a camera 317, respectively connected through a bus 320.

The CPU 301 is responsible for the overall control of the navigationapparatus 300. The ROM 302 records programs such as a boot program and adata update program. The RAM 303 is used as a work area of the CPU 301.The CPU 301 executes various programs recorded on the ROM 302 togenerally control the navigation apparatus 300, using the RAM 303 as awork area.

The magnetic disk drive 304 controls the reading/writing of data withrespect to the magnetic disk 305 under the control of the CPU 301. Themagnetic disk 305 records the data written under the control of themagnetic disk drive 304. The magnetic disk 305 may be HD (hard disk) orFD (flexible disk), for example.

The optical disk drive 306 controls the reading/writing of data withrespect to the optical disk 307 under the control of the CPU 301. Theoptical disk 307 is a removable recording medium having data read outunder the control of the optical disk drive 306. A writable recordingmedium may be utilized for the optical disk 307. The removable recordingmedium may be a medium other than the optical disk 307, such as an MOand a memory card.

Exemplary information recorded on the magnetic disk 305 includes mapdata and function data. The map information includes background datarepresenting features such as buildings, rivers, and ground surfaces,and road shape data indicative of road shapes, and is made up of datafiles sorted by districts.

The road shape data also include traffic condition data. The trafficcondition data include, for example, information indicative of thepresence of traffic lights, crosswalks, and presence of entrances/exitsand junctions of expressways for the nodes, and lengths (distances) oflinks, road widths, directions of travel, road types (such asexpressway, toll road, general road), etc., for the links.

The function data are three-dimensional data indicative of shapes offacilities on the map, text data indicative of explanations of thefacilities, and various data other than the map data. The map data andthe function data are recorded in a state of blocks sorted by districtor function. Specifically, for example, the map data are recorded inblocks sortable by district such that respective blocks representpredetermined districts on the map displayed on a display screen. Forexample, the function data are recorded in multiple blocks sortable byfunction such that each block implements one function.

The function data are data including data implementing functions ofprogram data that implement route search, calculation of time required,route guide, etc., in addition to the three-dimensional data and thetext data described above. The map data and the function data are sortedinto data files according to district and function, respectively.

The audio I/F 308 is connected to the microphone 309 for audio input andthe speaker 310 for audio output. Sounds received by the microphone 309are A/D-converted within the audio I/F 308. The microphone 309 isdisposed near a sun visor of the vehicle and one or more of themicrophones 309 may be disposed. The speaker 310 outputs sounds ofpredetermined audio signals subjected to D/A conversion in the audio I/F308. The sounds input from the microphone 309 may be recorded as audiodata on the magnetic disk 305 or the optical disk 307.

The input device 311 includes a remote controller having keys forentering characters, numeric values, and various instructions; akeyboard; a touch panel; etc. The input device 311 may be implemented insingle form such as a remote controller, a keyboard, and a touch panel,or may be implemented in multiple forms.

The video I/F 312 is connected to the display 313. Specifically, thevideo I/F 312 is made up of, for example, a graphic controller thatgenerally controls the display 313, a buffer memory such as VRAM (VideoRAM) that temporarily records immediately displayable image information,and a control IC that controls the display 313 based on image dataoutput from a graphic controller.

The display 313 displays icons, cursors, menus, windows, or various datasuch as characters and images. The display 313 draws the above map datatwo-dimensionally or three-dimensionally. The map data displayed on thedisplay 313 can be superimposed with a mark, etc., representative of thecurrent position of the vehicle equipped with the navigation apparatus300. The current position of the vehicle is calculated by the CPU 301.

For example, a CRT, a TFT liquid crystal display, a plasma display,etc., may be employed as the display 313. The display 313 is disposednear the dashboard of the vehicle. The display 312 may be disposed inplural in the vehicle in such a way that the displays are disposed inthe vicinity of the backseat of the vehicle as well as near thedashboard of the vehicle.

The communication I/F 314 is wirelessly connected to a network andfunctions as an interface between the navigation apparatus 300 and theCPU 301. The communication I/F 314 is wirelessly connected to acommunication network such as the internet and also functions as aninterface between this communication network and the CPU 301.

The communication network includes LAN, WAN, public line network,portable telephone network, etc. Specifically, the communication I/F 314is made up of, for example, an FM tuner, VICS (Vehicle Information andCommunication System)/beacon receiver, a radio navigation device, andother navigation devices and acquires road traffic information, such asroad congestion and traffic regulations, distributed from VICS centers.VICS is a registered trademark.

The GPS unit 315 receives signals from GPS satellites and outputsinformation indicative of the current position of the vehicle. Theinformation output from the GPS unit 315 is used along with valuesoutput from the various sensors 316 (described hereinafter) when the CPU301 calculates the current position of the vehicle. The informationindicative of the current position is information specifying one pointon map information, for example, latitude/longitude and altitude.

The various sensors 316 are those outputting information for determiningthe position and behavior of the vehicle, such as a vehicular speedsensor, an acceleration sensor, and an angular-speed sensor. The valuesoutput from the various sensors 316 are used by the CPU 301 forcalculating the current position of the vehicle and calculating changesin velocity and direction. The various sensors 316 output informationfor determining a state inside the vehicle and information fordetermining a state of the driver. Specifically, the information fordetermining a state inside the vehicle is information such astemperature, humidity, amount of smoke, and components of air inside thevehicle. Specifically, the information for determining a state of thedriver is information such as heart rate, brain waves, and respirationof the driver.

The camera 317 captures images inside or outside the vehicle. The imagesmay be still images or moving images and, for example, the camera 317captures images of behaviors of a passenger inside the vehicle andoutputs the captured images to a recording medium such as the magneticdisk 305 and the optical disk 307 through the video I/F 312. The camera317 captures images of conditions outside the vehicle and outputs thecaptured images to the recording medium such as the magnetic disk 305and the optical disk 307 through the video I/F 312. The camera 317 hasan infrared camera function, and distributions of surface temperaturesof objects present inside the vehicle may relatively be compared basedon the image information captured with the use of the infrared camerafunction. The images output to the recording medium are overwritten andsaved.

The functions of the image acquiring unit 101, the dividing unit 102,the calculating unit 103, the notifying unit 104, the determining unit105, and the control unit 106 included in the drive control apparatus100 depicted in FIG. 1 are implemented by the CPU 301 executingpredetermined programs to control the units of the navigation apparatus300 with the use of programs and data recorded on the ROM 302, the RAM303, the magnetic disk 305, the optical disk 307, etc., of thenavigation apparatus 300 depicted in FIG. 3.

The navigation apparatus 300 of the example can execute the drivecontrol program recorded on the ROM 302 serving as the recording mediumin the navigation apparatus 300 to implement the functions of the drivecontrol apparatus 100 depicted in FIG. 1 in the drive control processingprocedures depicted in FIG. 2.

(Functional Configuration of Drive Control Apparatus)

The functional configuration of the drive control apparatus according tothe example will be described with reference to FIG. 4. FIG. 4 is ablock diagram of a functional configuration of the drive controlapparatus according to the example. As depicted in FIG. 4, a drivecontrol apparatus 400 includes a driving unit 401, a control unit 402, astorage unit 403, an information input unit 404, an information outputunit 405, a vehicle information I/F 406, an external device I/F 407, animage processing unit 408, and a sensor unit 410. The drive controlapparatus 400 may be integrated with or independent of the navigationapparatus 300. Some functions may be configured to be shared.

The driving unit 401 is controlled by the controlling unit 402 fordriving in the yaw direction and the pitch direction and enables drivingwith multiple degrees of freedom such as roll directions associated withthese directions. The driving unit 401 may be equipped with one or moreof the sensors of the sensor unit 410 described hereinafter. The drivingunit 401 may be disposed at a position within the visual field of thedriver of the vehicle and enabling acquisition of information of thesurroundings of the vehicle. For example, if the driving unit 401 isequipped with an image sensor unit 411, the driving unit 401 equippedwith the image sensor unit 411 is disposed on the upper side of thedashboard or near a rearview mirror.

The driving unit 401 may be a robot in a shape of a human or an animal.In this case, the driving unit 401 may include all or some ofconstituent units described hereinafter. Specifically, for example, theinformation output unit 405 is included to present information to a userby displaying an image or outputting sounds. The driving unit 401 movesto present information to a user. For example, the driving unit 401raises an arm or shakes the head to present information to a user.

If the driving unit 401 is equipped with a camera serving as the imagesensor unit 411, the driving unit may change the shooting direction ofthe camera. Specifically, for example, the view angles of a camera are40 degrees horizontally and 30 degrees vertically in the case of normaldigital cameras or movie cameras. Therefore, the camera can captureimages in a wide range by varying the visual field direction by thedriving unit 401.

The control unit 402 controls the driving unit 401. Specifically, thecontrol unit 402 outputs control signals for controlling the drivingunit 401 to the driving unit 401. Specifically, for example, the controlunit 402 outputs a control signal for rotating the driving unit 401 inthe yaw direction or the pitch direction and control signals forcontrolling the turning on/off of various sensors to the driving unit401. If the driving unit 401 is a robot in a shape of a human or ananimal, the control unit 402 may concurrently control multiple outputssuch as an output of light, audio, and motion.

The storage unit 403 stores various types of information. Informationstored in the storage unit 403 includes map information, for example.The map information includes road network data consisting of nodes andlinks and image data drawn with the use of features for facilities,roads, and other land shapes (mountains, rivers, and lands). The mapdata may include text information, information of names and addresses offacilities, images of roads and facilities.

The map information also includes types and positions of road signs andbillboards, positions of traffic signals, ranges of school zones, etc.The storage unit 403 stores the vehicle information, the imageinformation, the coordinate values of points, the danger index, etc.,acquired by the information input unit 404, the vehicle information I/F406, the external device I/F 407, and the sensor unit 410.

The information input unit 404 inputs various types of information. Forexample, a touch sensor unit 425, a sound sensor unit 415, or the imagesensor unit 411 may implement the function thereof and specificallyincludes a touch panel, a remote controller, a mouse, a touch sensor, amicrophone, a camera, etc. The information output unit 405 outputsvarious types of information. Specifically, for example, the informationoutput unit 405 includes a display screen that displays images, anoutput device that outputs sounds, etc.

The vehicle information I/F 406 acquires vehicle information concerningvehicular speed and the operation of the vehicle. Specifically, forexample, the vehicle information is information concerning operationssuch as turn indicators, hazard lamps, steering angles, lights, andwipers and information concerning vehicular speed from an accelerationsensor unit 413, etc. The vehicle information I/F 406 may acquireinformation from inside the vehicle. Specifically, for example, thevehicle information I/F 406 may acquire information concerning thebehavior of the driver or conditions such as temperature, humidity,components of air, etc., inside the vehicle.

The external device I/F 407 functions as an interface with externaldevices and is connected with various external devices. For example, theexternal device I/F 407 identifies the position of the vehicle withinformation from GPS satellites. The external device I/F 407 refers tothe map information in a map information database, etc. The externaldevice I/F 407 connects to the navigation apparatus 300 to set a routeto a destination. The function of the external device I/F 407 may beimplemented by a GPS sensor unit 414 and the storage unit 403.

The image processing unit 408 uses the information stored in the storageunit 403 and the image information acquired from the image sensor unit411 to process images. Specifically, for example, the image processingunit 408 recognizes directions and speeds of moving objects, road signs,and billboards. The sensor unit 410 includes various sensor units.Specifically, for example, the sensor unit 410 includes a sensor thatacquires information about a state of the vehicle, a sensor thatacquires information about a state of the driver, etc.

The image sensor unit 411 acquires image information. Specifically, forexample, images inside or outside the vehicle are captured by a CCDcamera, etc., to acquire the image information. A driving-unit positiondetecting unit 412 detects a position or rotation of the driving unit401. Specifically, the drive angles in the yaw direction and the pitchdirection of the driving unit 401 are detected.

The acceleration sensor unit 413 detects acceleration of the vehiclewith a gyroscope, etc. The acceleration of the vehicle may be theacceleration in the longitudinal direction for detecting changes in thevehicle speed or may be the acceleration in the lateral direction fordetecting the vibrations of the vehicle. The GPS sensor unit 414 detectsthe current position of the vehicle based on electric waves from the GPSsatellites. The sound sensor unit 415 acquires the loudness of sound andthe direction of emission of sound inside or outside the vehicle througha microphone, etc.

A temperature sensor unit 416 measures temperature inside or outside thevehicle. A humidity sensor unit 417 measures humidity inside or outsidethe vehicle. An illuminance sensor unit 418 measures the intensity oflight inside or outside the vehicle. Specifically, for example, thesensor detects whether the vehicle has entered a tunnel and whether thesun is shining. The illuminance sensor unit 418 may detect an amount ofultraviolet light in sunlight. A smoke sensor unit 419 detects smokeinside or outside the vehicle. Specifically, for example, cigarettesmoke is detected. An air sensor unit 420 measures components of theair. Specifically, for example, the carbon monoxide concentration or theimpurity concentration inside the vehicle is measured.

An ultrasonic sensor unit 421 measures the distance to an object inproximity of the vehicle. Specifically, the ultrasonic sensor unit 421measures the time until ultrasonic waves emitted from the ultrasonicsensor unit 421 mounted on the vehicle return to the vehicle to measurethe distance from the vehicle to the object to be measured. Themicrowave sensor unit 422 measures a distance to an object in proximityof the vehicle. Specifically, microwaves are used to measure thedistance from the vehicle to the object. A laser sensor unit 423measures the distance to an object in proximity of the vehicle.Specifically, a laser beam is used to measure a distance from thevehicle to the object.

An infrared sensor unit 424 uses infrared light to acquire imageinformation. The touch sensor unit 425 determines whether an arbitraryobject contacts an objective part inside or outside the vehicle. Apressure sensor unit 426 measures air pressure inside the vehicle andforces applied to the sensors. A biological sensor 427 acquiresinformation such as heart rate, brain waves, respiration, etc., of auser. The magnetic sensor unit 428 measures a magnetic force.

(Schematic of Processing by Drive Control Apparatus)

A schematic of processing by the drive control apparatus 400 will bedescribed. FIG. 5 is a flowchart of processing performed by the drivecontrol apparatus according to the example. As depicted in the flowchartof FIG. 5, the drive angle of the driving unit 401 is initialized (stepS501). Specifically, for example, the angles of the driving unit 401 areset to 0 degrees in the yaw direction and the pitch direction.

The vehicle information and the image information are acquired (stepS502). It is determined whether a turn indicator is used based on thevehicle information acquired at step S502 (step S503) and if a turnindicator is used (step S503: YES), a first attention point iscalculated (step S504). On the other hand, if a turn indicator is notused (step S503: NO), the processing returns to step S502, andsubsequent processes are repeated. The first attention point is anattention point for time T. The attention point is a reference point ona road when calculating a danger index of the vehicle.

The first attention point calculated at step S504 is used to calculate acontrol signal to the driving unit 401 (step S505). The control signalis an electric signal that controls the driving unit 401. When thecontrol signal calculated at step S505 is input to the driving unit 401,it is determined whether the first attention point calculated at stepS504 falls within a photographable range (step S506). At step S506, thephotographable range is a range of the view angles of a camera.

If the first attention point falls within the photographable range (stepS506: YES), the driving unit 401 is controlled by the control signalcalculated at step S505 (step S507). On the other hand, if the firstattention point does not fall within the photographable range (stepS506: NO), the processing returns to step S501, and subsequent processesare repeated.

Image information is acquired by the camera mounted on the driving unit401 controlled at step S507 (step S508) and the danger index iscalculated based on this image information and the vehicle informationacquired at step S502 (step S509); and a second attention point iscalculated (step S510). The second attention point is an attention pointfor time (T+ΔT).

It is determined whether the danger index calculated at step S509 is atleast equal to a threshold value A (step S511), and if the danger indexis equal to or more than the threshold value A (step S511: YES), it isfurther determined whether the danger index is at least equal to athreshold value B (step S512). It is assumed that the threshold valueA<the threshold value B. If the danger index is equal to or more thanthe threshold value B (step S512: YES), recovery to normal vehicularoperation is waited for (step S513: NO), and if recovery to normalvehicular operation is achieved (step S513: YES), it is determinedwhether the control of the driving unit 401 is to be continued (stepS514). If the control is not to be continued at step S514 (step S514:NO), the series of processing ends.

On the other hand, if the danger index is less than the threshold valueA at step S511 (step S511: NO), the processing returns to step S505, andsubsequent processes are repeated. If the danger index is less than thethreshold value B at step S512 (step S512: NO), the driver is warned(step S515) and the processing returns to step S505, and subsequentprocesses are repeated.

The processing by the drive control apparatus 400 at each operationdescribed in FIG. 5 will be described in detail with reference to FIGS.6 to 21. This example uses a camera having functional performances ofthe lens field angles (W, H)=(40°, 30°) and the resolutions (W, H)=(640,480). W indicates a range in a direction of width and H indicates arange in a direction of height. It is assumed that no uneven part existson the road on which the vehicle is traveling. The range of the driveangle of the driving unit 401 corresponds to a range from −90° to +90°in the yaw direction, assuming that the angle of the straight forwarddirection is 0° and that the rightward direction is the positivedirection, and is a range from −45° to +45° in the pitch direction,assuming that the angle of the direction parallel to the road and thatthe downward direction is the positive direction.

(Initializing Drive Angle Processing)

The processing for initializing the drive angle at step S501 of FIG. 5will be described in detail. The initialization of the drive angle isperformed by the control unit 402 setting the angles of the driving unit401 to 0° in the yaw direction and 0° in the pitch direction.

(Processing for Acquiring Vehicle Information and Image Information)

The processing for acquiring the vehicle information and the imageinformation at step S502 of FIG. 5 will be described in detail withreference to FIG. 6. FIG. 6 is a flowchart of the processing foracquiring the vehicle information and the image information. As depictedin the flowchart of FIG. 6, the vehicle information and the imageinformation are acquired (step S601).

The vehicle information is information acquired by the vehicleinformation I/F 406 and specifically is information concerning the turnindicator and information concerning the vehicle speed. The imageinformation is information acquired by the image sensor unit 411 andspecifically is information concerning images of the surroundings of thevehicle captured by a camera, etc. The vehicle information and the imageinformation acquired at step S601 are stored in the storage unit 403(step S602), and a series of the processing ends.

(Processing for Calculating the First Attention Point)

The processing for calculating the first attention point at step S504 ofFIG. 5 will be described in detail with reference to FIGS. 7 to 10. FIG.7 is a flowchart of the processing for calculating the first attentionpoint. As depicted in the flowchart of FIG. 7, the vehicle informationand the image information stored in the storage unit 403 at step S602 ofFIG. 6 are read out (step S701). At step S701, the image information isassumed to be captured by a camera disposed at a height of one meterfrom the road with an angle of 0° in the pitch direction.

Calculation of an actual distance between a point on the road and thecamera in the captured image will be described for a case in which acamera is disposed at a height of one meter from the road. FIG. 8 is anexplanatory diagram of a vertical distance of a point on the road in thecaptured image. As depicted in FIG. 8, if a camera with a lens fieldangle of 30° in the direction of height is disposed at a height of onemeter from the road, a distance from the camera to the lowest point ofthe road in the image is calculated from 1×(1/tan 15°. A distance fromthe camera to the center point of the road in the lower-half imageacquired by vertically dividing the image is calculated from 1×(1/tan15°.

FIG. 9 is an explanatory diagram of a relation between a horizontaldistance and a vertical distance from the center point of the capturedimage. As depicted in FIG. 9, assuming that the y-coordinates and thex-coordinates represent the lower direction and the rightward direction,respectively, from the image center point in the image and that ahorizontal distance from a point of coordinates (x, y) to the camera isD1, since the range of the resolution of the camera is 480 in thedirection of height, D1=1×(1/tan 15°)×(240/y) [Eq. 1]. Assuming that avertical distance to the optical axis of the camera at a point ofcoordinates (x, y) is D2, since the range of the lens field view of thecamera is 40° in the lateral direction and the range of the resolutionis 640 in the lateral direction, D2=D1×(1/tan 20°)×(x/320) [Eq. 2].

A discontinuity of the road edge in the turn direction is detected basedon the vehicle information and the image information read at step S701(step S702). Specifically, a direction indicated by the turn indicatoris determined as the turn direction from turn-indicator in the vehicleinformation and the discontinuity of the road edge is detected byanalyzing the image information.

FIG. 10 is an explanatory diagram for explaining points on a road. FIG.10 depicts a point of discontinuity of the road edge in the turndirection farther from the vehicle (point A), a point of discontinuityof the road edge in the turn direction closer to the vehicle (point B),a reference point of the road beyond the turn (point C), and the firstattention point (point D). The points A, B, C, and D are assumed to bepresent on the road. Two points, i.e., the points A and B are detectedfor the discontinuity of the road edge at step S702.

A length L of the discontinuity of the road edge is calculated (stepS703). The length L of the discontinuity of the road edge is a lengthbetween the point A and the point B detected at step S702. The referencepoint of the road after the turn (point C) is then detected (step S704).The point C is a point on the line between the point A and the point Bwhere the distance between A and C is ¼ of the distance between A and Bin the case of the left-hand traffic. In other words, the point C is thecenter point of the road on which the vehicle travels after turning ontothe road according to the indication of the turn indicator.

The first attention point (point D) is determined depending on thereference point detected at step S704 (step S705). The point D is apoint apart from the point C, perpendicular to the optical axis of thecamera at a distance equivalent to the distance between A and B. Thecoordinate value of the first attention point determined at step S705 isstored in the storage unit 403 (step S706), a series of the processingends.

The coordinate value of the point D is obtained as follows. If thecoordinate value of the point A in the image is Pa=(120, 40), a distance(D1 a, D2 b) to the point A from the camera is obtained as (D1 a, D2a)=(6/tan 15°, 2×(tan 20°/tan 15°) from [Eq. 1] and [Eq. 2]. If thecoordinate value of the point B in the image is Pb=(160, 60), a distance(D1 a, D2 b) to the point A from the camera is obtained as (D1 b, D2b)=(4/tan 15°, 2×(tan 20°/tan 15°) from [Eq. 1] and [Eq. 2].

Therefore, the distance Dab between A and B is Dab=7.5 meters from thetheorem of three squares. Therefore, the coordinate value Pc of thepoint C in the image is Pc=(130, 45). Since the coordinate value Pd ofthe point D in the image is located apart from Pc at a distance Dab tothe right of the traveling direction perpendicularly to the cameraoptical axis, the value is Pd=(253, 45).

(Processing for Calculating Control Signal)

The processing for calculating the control signal at step S505 of FIG. 5will be described in detail with reference to FIG. 11. FIG. 11 is aflowchart of the processing for calculating the control signal. Asdepicted in FIG. 11, the coordinate value of the first attention pointstored in the storage unit 403 at step S706 of FIG. 7 is read out (stepS1101). The rotation angles are calculated from the coordinate value ofthe first point read out at step S1101 (step S1102).

At step S1102, when the rotation angles are calculated, specifically,assuming that the coordinates of the point D is Pd=(x, y), a rotationangle θ in the yaw direction for overlapping the image center point withthe point D is represented by θ=tan−1(tan 20(x/320)) and a rotationangle φ in the pitch direction is represented by φ=tan−1(tan 15(y/240)).Therefore, substituting the coordinate value (253, 45) of the point Dstored in the storage unit 403 at step S706 of FIG. 7, θ=tan−1(tan20(253/320))=16 and φ=tan−1(tan 15(45/240))=3 are obtained. The controlsignal corresponding to the rotation angles (θ, φ)=(16, 3) calculated atstep S102 is stored in the storage unit 403 (step S1103), and a seriesof the processing ends.

(Processing for Controlling the Driving Unit)

The processing for controlling the driving unit at step S507 of FIG. 5will be described in detail with reference to FIG. 12. FIG. 12 is aflowchart of the processing for controlling the driving unit. Asdepicted in FIG. 12, the control signal stored in the storage unit 403at step S1103 of FIG. 11 is read out (step S1201). The driving unit 401is controlled by the control signal read out at step S1201 (step S1202),and a series of the processing ends.

The control of the driving unit 401 is performed by rotating the camerato an angle to capture the point D described in FIGS. 7 to 10 in theimage captured by the camera, for example. Specifically, when the camerais controlled and rotated by the rotation angle θ in the yaw directionand the rotation angle φ in the pitch direction using the coordinatevalue of the point D calculated in FIG. 11, the point D is overlappedwith the center point of the image and, therefore, the point D iscaptured in the image.

(Processing for Acquiring Image Information)

The processing for acquiring the image information at step S508 of FIG.5 will be described in detail with reference to FIG. 13. FIG. 13 is aflowchart of the processing for acquiring the image information. Asdepicted in FIG. 13, the image information for time T is acquired by thecamera controlled at step S1202 of FIG. 12 (step S1301). Therefore, thecenter point of the image information is overlapped with the point D.

An attention-point template is acquired that is a range of 10×10 pixelscentering on the center point of the image information acquired at stepS1301 (step S1302). The attention-point template acquired at step S1302and the image information for time T are stored in the storage unit 403(step S1303). The image information is acquired when time ΔT has elapsedafter the image is acquired at step S1301, i.e., image information fortime (T+ΔT) (step S1304). The image information for time (T+ΔT) isstored at the storage unit 403 (step S1305), and a series of theprocessing ends.

(Processing for Calculating Danger Index)

The processing for calculating the danger index at step S509 of FIG. 5will be described in detail with reference to FIGS. 14 to 19. FIG. 14 isa flowchart of the processing for calculating the danger index. FIG. 15is an explanatory diagram of the image information acquired at time Tand FIG. 16 is an explanatory diagram of the image information acquiredat time (T+ΔT).

As depicted in the flowchart of FIG. 14, the image information for timeT is read from the storage unit 403 (step S1401). The image informationfor time T is the image information stored at step S1303 of FIG. 13 and,specifically, for example, the image information depicted in FIG. 15. Asdepicted in FIG. 15, and image of a road 1501 along which the vehicle istraveling, an animal 1502, and a person 1503 is captured. The imageinformation for time (T+ΔT) is read from the storage unit 403 (stepS1402). The image information for time (T+ΔT) is the image informationstored at step S1305 of FIG. 13 and, specifically, for example, theimage information depicted in FIG. 16. As depicted in FIG. 16, an imageof a road 1601 along which the vehicle is traveling, an animal 1602, anda person 1603 is captured.

The image information for time T read at step S1401 is superimposed onthe image for time (T+ΔT) read at step S1402 by matching white lines(step S1403). The matching of white lines is performed by overlappingwhite lines such as crosswalks, stop lines, white lines between trafficlanes, and white lines on the edges of the road. Specifically, forexample, image information depicted in FIG. 17 is acquired.

FIG. 17 is an explanatory diagram of the image information where whitelines are matched and overlapped. As depicted in FIG. 17, the road 1501of FIG. 15 and the road 1601 of FIG. 16 are superimposed by matching thewhite lines. Therefore, differences in ΔT may be represented for objectscaptured in the image exclusive of the road. Specifically, for example,the positions of the animal 1502 and the person 1503 at time T and thepositions of the animal 1602 and the person 1603 at time (T+ΔT) can beindicated simultaneously.

In the image information overlapped at step S1403, portions exhibitinglarge differences are detected as moving objects (step S1404).Specifically, the animal 1502 (or the animal 1602) and the person 1503(or the person 1602) are detected as moving objects. Attribute pointsare extracted in the moving object area (step S1405) to acquire atemplate near the attribute points (step S1406). The template acquiredat step S1406 is matched with the image information for time (T+ΔT) tocalculate a motion vector M (step S1407). Specifically, for example, amotion vector M1 and a motion vector M2 depicted in FIG. 18 arecalculated.

FIG. 18 is an explanatory diagram of the motion vector M. FIG. 18depicts the road 1501, 1602, the animal 1502, 1602, the person 1503,1603, and a vanishing point 1801. The motion vectors M depicted in FIG.18 indicate distances and directions of movement during ΔT. Therefore,M1 is the motion vector when the animal 1502 moves to the position ofthe animal 1602 during ΔT and M2 is the motion vector when the person1503 moves to the position of the person 1603 during ΔT.

A danger index D is calculated from the motion vector M calculated atstep S1407 and vehicle speed V (step S1408). The danger index D iscalculated with the use of a unit vector I having the attention point asthe start point and the end point direction toward the vanishing point1801 of the road, the motion vector M, and the vehicle speed V.Specifically, the danger index D is calculated from a product of anabsolute value of an inner product of the motion vector M and the unitvector I and the vehicle speed V. Assuming that a width of the roadafter the turn is L, D=|I·M|×V/(L/4) may be obtained. If the directionof the motion vector M is perpendicular to the unit vector I, the dangerindex D is calculated to be greater and if the direction of the motionvector M is parallel to the unit vector I, the danger index D iscalculated to be smaller.

FIG. 19 is an explanatory diagram of degrees of the danger index Ddepending on the relationship between the unit vector I and the motionvector M. FIG. 19 depicts the road 1601, the animal 1602, the person1603, the motion vector M1 of the animal, the motion vector M2 of theperson, the vanishing point 1801, the attention point 1901, and the unitvector I. Since the motion vector M2 of the person is perpendicular tothe unit vector I as depicted in FIG. 19, the danger index D becomeslarger. Since the motion vector M1 of the animal is parallel to the unitvector I, the danger index D becomes smaller. The danger index Dcalculated at step S1408 is stored (step S1409), and a series of theprocessing ends.

(Processing for Calculating the Second Attention Point)

The processing for calculating the second attention point at step S510of FIG. 5 will be described in detail with reference to FIG. 20. FIG. 20is a flowchart of the processing for calculating the second attentionpoint. As depicted in FIG. 20, the attention-point template for time Tacquired at step S1302 of FIG. 13 is read out (step S2001).

The image information for time (T+ΔT) stored at step S1305 of FIG. 13 isread, and the image information for time (T+ΔT) is matched with theattention-point template for time T to acquire the attention-pointtemplate for time (T+ΔT) (step S2002). The center coordinates of theattention-point template for time (T+ΔT) acquired at step S2202 aredefined as the second attention point and the coordinate value of thesecond attention point is stored in the storage unit 403 (step S2003),and a series of the processing ends.

(Processing for Determining whether Danger Index is at Least Equal toThreshold Values)

Detailed description will be made of the processing for determiningwhether the danger index is at least equal to the threshold values atstep S511 and step S512 of FIG. 5. For example, if the motion vector Mhas a component perpendicular to the unit vector I and if the length ofthe discontinuity of the road edge is L, |I·M|/(L/4)=1 is satisfied.Therefore, the danger index D=V is obtained and the vehicle speed V atthe turn is defined as the danger index D. Specifically, assuming that aslow speed is 20 km/h, it is determined that the danger index D is highif the danger index D is equal to or more than 20.

Assuming that the threshold value A at step S511 of FIG. 5 is 20 andthat the threshold value B at step S512 is 40, if the danger index D isless than 20, the processing returns to step S505 without warning thedriver and the control signal is calculated. If the danger index D isequal to or more than 20 and less than 40, the processing proceeds tostep S515 to warn the driver and returns to step S505 and the controlsignal is calculated. If the danger index D is equal to or more than 40,the processing proceeds to step S531 without warning the driver and therecovery of normal vehicular operation is waited for.

(Processing for Determining whether Recovery of Normal VehicularOperation has been Achieved)

The processing at step S513 of FIG. 5 for determining whether therecovery of normal vehicular operation has been achieved will bedescribed in detail with reference to FIG. 21. FIG. 21 is a flowchart ofthe processing for determining whether the recovery of normal vehicularoperation has been achieved. As depicted in FIG. 21, it is determinedwhether the vehicle speed is zero (step S2101). If the vehicle speed iszero at step S2101 (step S2101: YES), it is determined that recovery ofnormal vehicular operation has been achieved (step S2102), and a seriesof the processing ends.

If the vehicle speed is not zero at step S2101 (step S2101: NO), it isdetermined whether the steering angle is zero for at least a certaintime period (step S2103). If the steering angle is zero for a certaintime period or more at step S2103 (step S2103: YES), the processingproceeds to step S2102 determining that recovery of normal vehicularoperation has been achieved, and a series of the processing ends. If thesteering angle is not zero for a certain time period or more at stepS2103 (step S2103: NO), dangerous vehicular operation is determined(step S2104), the processing returns to step S2101 and subsequentprocesses are repeated.

(Processing for Warning Driver)

The processing for warning the driver at step S515 of FIG. 5 will bedescribed in detail. If dangerous vehicular operation is determined atstep S2104 of FIG. 21, the drive control apparatus 400 warns the driver.The warning to the driver is given by images or sounds output from theinformation output unit 405 or the motion of the driving unit 401, forexample. Alternatively, the warning of the dangerous vehicular operationis given to the driver through a combination thereof.

Although the processing returns to step S505 if the danger index is lessthan the threshold value A at step S511: NO of FIG. 5 and the processingproceeds to step S515 to warn the driver and returns to step S505 if thedanger index is less than the threshold value B at step S512: NO in thisexample, configuration is not limited hereto. Specifically, for example,the driving unit 401 is controlled to continue tracking the movingobjects. The driving index may specially be calculated for these movingobjects to further avoid danger.

Although the danger index is calculated from the relationship ofpositions of objects with the use of the image information in thisexample, configuration is limited hereto. For example, the danger indexmay be a value greater than that of the normal vehicular operation whenturning right or left, changing lanes, watching road signs/billboards,passing areas having a high incidence of accidents, traveling on anarrow road, passing interchange points of express ways, etc.

Specifically, when turning right or left, the danger index is calculatedfrom the turn indicator information. When turning left, the turning tothe left is detected from the turn indicator information and the dangerindex is set to a value larger than that of normal vehicular operation.In the case of left-hand traffic, the danger index is set to a largervalue when turning right than turning left since the opposite lane istraversed. Therefore, when turning right, the turning to the right isdetected from the turn indicator information and the danger index is setto a value larger than that of the time of turning left.

When watching road signs/billboards, passing areas having a highincidence of accidents, passing interchange points of express ways,etc., the map information is used to calculate the danger index. Forexample, if the current position of the vehicle on the map informationcomes close to school zones, important road signs/billboards on theroute to the destination, accident-prone areas, interchange points ofexpress ways, etc., the danger index is set to a value larger than thatof normal vehicular operation.

Similarly, when changing lanes, traveling on a narrow road, etc., thedanger index is calculated from the road conditions and informationconcerning other vehicles. For example, the vehicle information I/F 406,the external device I/F 407, and the image sensor unit 411 are used tocalculate a width of the road and detect a lane change, and the dangerindex is set larger than that of normal vehicular operation if thevehicle travels on a narrow road or changes lanes.

In other cases of calculating the danger index depending on externalsituations, the sound sensor unit 415 acquires sounds to determinewhether the driving condition is highly stressful and the danger indexis set larger than that of normal vehicular operation, for example, whena horn is blown outside. Another example of calculating the danger indexdepending on external circumstances is that the danger index may be setlarger than that of normal vehicular operation when it rains heavilybased on a determination made according to weather information acquiredfrom a portable terminal through the external device I/F 407, imageprocessing by the image sensor unit 411, the sound of rain acquired bythe sound sensor unit 415, etc.

The danger index may be calculated from a change in the state of thedriver. For example, if it is determined that the driver feels sleepyfrom the information acquired from the image sensor unit 411, theacceleration sensor unit 413, the biological sensor 427, etc., thedanger index is set larger than that of normal vehicular operation. Thethreshold value A and the threshold value B of the step S511 and stepS512 of FIG. 5 may be set to smaller values. The shooting direction ofthe image sensor unit 411 may be turn toward the driver depending ondetermined a degree of sleepiness. The state of the driver may bedetermined in detail from captured image information to calculate thedanger index.

Specifically, when calculating the danger index from a change in thestate of the driver, the image information outside the vehicle capturedby the image sensor unit 411 is used to determine whether the vehicledeviates from the lane, and if is determined that the deviation isdangerous, the danger index is set larger than that of normal vehicularoperation. The image information inside the vehicle captured by theimage sensor unit 411 may be used to detect the number and lengths ofeye blinks by the driver and the danger index may be set larger thanthat of normal vehicular operation depending on the detection result.

Specifically, when calculating the danger index from a change in thestate of the driver, vibrations of the vehicle may be detected with theacceleration sensor unit 413 and the sleepiness of the driver may bedetected from the vibrations of the vehicle to set the danger indexlarger than that of normal vehicular operation. Specifically, whencalculating the danger index from a change in the state of the driver,the heart rate, brain waves, respiration, etc., of the driver may bedetected with the biological sensor 427 and if it is determined that thedriver feels sleepy, is under high stress, or is excessively tense, thedanger index may be set larger than that of normal vehicular operation.

The danger index may be calculated according to the informationconcerning the vehicle acquired by the vehicle information I/F 406.Specifically, for example, if the turn indicator or wiper is operated,the danger index is set larger than that of normal vehicular operation.If the hazard lamp is turned on or if the headlights are turned on, thedanger index is set larger than that of normal vehicular operation. Ifthe vehicle speed is greater than the speed limit defined in the mapinformation or recognized from the road signs/billboards, the dangerindex may be set larger than that of normal vehicular operation, and ifa difference in the steering angle is equal to a predetermined value ormore as compared to the map information, the danger index may be setlarger than that of normal vehicular operation.

The danger index may be set larger than that of normal vehicularoperation depending on the distance to the preceding vehicle. Forexample, the distance to the preceding vehicle is acquired by sensorsthat acquire the distance to an object such as the image sensor unit411, the ultrasonic sensor unit 421, the infrared sensor unit 424, etc.,and if the distance to the preceding vehicle is less than apredetermined distance or if the relative speed to the preceding vehicleis a predetermined value or more, the danger index may be set largerthan that of normal vehicular operation. If the image sensor unit 411,etc., recognizes that the hazard lamp of the preceding vehicle is turnedon, the danger index may be set larger than that of normal vehicularoperation.

As described above, according to the navigation apparatus 300 or thedrive control apparatus 400 of the example, the calculating unit 103calculates a danger index indicative of the possibility of occurrence ofa dangerous event for the mobile body based on the informationconcerning the mobile body acquired by the information acquiring unit101, and the control unit 106 can control the driving unit 102 thatdrives the sensor mounted on the mobile body based on the calculationresult calculated. Therefore, the driving unit 102 can be controlled ifit is determined that a dangerous event will occur for the mobile bodyeven when a user does not watch the driving unit 102, for example. Thisenables the driving unit 102 to be controlled and prevented frominterfering with the judgment of the user while operating the vehicleunder dangerous circumstances.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, a passenger of the mobile body can be notified ofthe possibility of occurrence of a dangerous event for the mobile bodybased on the calculation result calculated by the calculating unit 103.Therefore, the navigation apparatus 300 or the drive control apparatus400 can give a warning of dangerous vehicular operation to a driver ifthe danger index is within a predetermined range. This enables a user toknow that circumstances are dangerous and to avoid a dangerous eventsuch as an accident.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, the control unit 106 can stop the drive of thedriving unit 102 if the determining unit 105 determines that the dangerindex is a value greater than a predetermined value. Therefore, thenavigation apparatus 300 or the drive control apparatus 400 can stop thedriving unit 102 within the visual field of the driver during dangerouscircumstances to prevent the driving unit 102 from being mistaken for anobject outside the vehicle (such as a person or an oncoming vehicle).This enables a user to concentrate on operating the vehicle since nodistractive motion exists within the visual field.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, the driving unit 102 can drive the informationacquiring unit 101. Therefore, a wide range of information can beacquired by driving the information acquiring unit 101 by the drivingunit 102. This enables a user to extensively detect the possibility ofoccurrence of a dangerous event.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, the information acquiring unit 101 can acquire imageinformation concerning the surroundings of the mobile body. Therefore,an object with a higher danger index for the mobile body may beidentified from changes in the acquired image information. This enablesa user to avoid a dangerous event such as an accident.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, the drive of the driving unit 102 can be resumed ifthe determining unit 105 determines that the danger index returns to avalue smaller than the predetermined value. Therefore, the driving unit102 may be driven during normal vehicular operation. This enables a userto resume the motion of a robot, etc., mounted on the vehicle after adangerous event has been avoided even if the motion was terminated.

According to the navigation apparatus 300 or the drive control apparatus400 of the example, the driving unit 102 can drive a sensor mounted onthe mobile body in the yaw direction and the pitch direction. Therefore,the drive control apparatus 100 can extensively detect informationconcerning the mobile body. This enables a user to extensively detectthe possibility of occurrence of a dangerous event.

As described above, according to the drive control apparatus, the drivecontrol method, the drive control program, and the recording medium ofthe present invention, the navigation apparatus 300 or the drive controlapparatus 400 can calculate the danger index based on the informationacquired by various sensors included in the sensor unit 410 and cancontrol the driving unit 102 if the danger index is equal to thethreshold value or more. Therefore, the driving unit 401 can beterminated at the time of dangerous vehicular operation even when thedriver does not watch at the driving unit 401. This enables the driverto concentrate on operating the vehicle since no distractive motionexists within the visual field.

The drive control method explained in the present embodiment can beimplemented by a computer, such as a personal computer and aworkstation, executing a program that is prepared in advance. Theprogram is recorded on a computer-readable recording medium such as ahard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executedby being read out from the recording medium by a computer. The programcan be a transmission medium that can be distributed through a networksuch as the Internet.

1-10. (canceled)
 11. A drive control apparatus comprising: a drivingunit that presents information to a passenger in a mobile body; aninformation acquiring unit that acquires information concerning themobile body; a calculating unit that, based on the information acquiredby the information acquiring unit, calculates a danger index indicativeof a possibility of occurrence of a dangerous event for the mobile body;a determining unit that determines whether the danger index calculatedby the calculating unit is greater than a given value; and a controlunit that controls the driving unit based on a calculation resultcalculated by the calculating unit, wherein the control unit terminatesdriving by the driving unit when the determining unit determines thedanger index to be greater than the given value.
 12. The drive controlapparatus according to claim 11, further comprising a notifying unitthat notifies the passenger of the possibility of occurrence of adangerous event for the mobile body, based on the calculation resultcalculated by the calculating unit.
 13. The drive control apparatusaccording to claim 11, wherein the driving unit drives the informationacquiring unit.
 14. The drive control apparatus according to claim 11,wherein the information acquiring unit acquires image informationindicative of surroundings of the mobile body.
 15. The drive controlapparatus according to claim 11, wherein the control unit resumes thedriving by the driving unit when the determining unit determines thatthe danger index has returned to a value less than the given value. 16.The drive control apparatus according to claim 11, wherein the drivingunit drives, in a yaw direction and a pitch direction, a sensor mountedon the mobile body.
 17. A drive control method comprising: acquiringinformation concerning a mobile body; calculating, based on theinformation acquired at the acquiring, a danger index indicative of apossibility of occurrence of a dangerous event for the mobile body;determining whether the danger index calculated at the calculating isgreater than a given value; and controlling, based on a calculationresult calculated at the calculating, a driving unit that presentsinformation to a passenger on the mobile body, wherein the controllingfurther includes terminating driving by the driving unit when at thedetermining, the danger index is determined to be greater than the givenvalue.
 18. A computer-readable recording medium storing therein adriving control program that causes a computer to execute: acquiringinformation concerning a mobile body; calculating, based on theinformation acquired at the acquiring, a danger index indicative of apossibility of occurrence of a dangerous event for the mobile body;determining whether the danger index calculated at the calculating isgreater than a given value; and controlling, based on a calculationresult calculated at the calculating, a driving unit that presentsinformation to a passenger on the mobile body, wherein the controllingfurther includes terminating driving by the driving unit when at thedetermining, the danger index is determined to be greater than the givenvalue.